URIteacherknowledge - Evolutionary structures

Rhode Island Department of Education
Lesson Plan

Lesson Title: Structures: One of these things is not like the other

State Standards: GLEs/GSEs

LS3- Groups of organisms show evidence of change over time (structures, behaviors and biochemistry).

8a illustrating that when an environment changes, the survival advantage /disadvantage of some characteristics may change

National Standards:

Standard A: Science as Inquiry
Standard C: Life Science subtopic three-biological evolution

Context of Lesson:

THis lesson will focus on the differences between homologous, analogous, and vestigial structures. Students will be shown several different animals and some of their structures that have either similar function or structure. Students will be given the chance to test for themselves how structures could have evolved from other organisms to be functional or non-functional or differently functioning based on the organism. The diferent structures fit the organisms to their environment and provide them with the advantage in that environment.

Opportunities to Learn:

Depth of Knowledge

DOK-level 2: describe the relationship of structures; explain the difference between homologous, analogous, and vestigial structure
DOK-level 3: make connections to similar structures and how the functionality has changed from organism to organism

Prerequisite Knowledge

-human bone structures
-function means the purpose that something serves (what does it do?)
-structure means the way something is made or what it looks like

Plans for Differentiating Instruction

-visual: comparing pictures
-auditory: directions explained
-bodily-kinesthetic: lab stations, writing paragraphs

Accommodations and modifications

Students with documented learning disabilities will receive the handouts one class day ahead of the lesson

Environmental factors

The classroom is set up with 12 two-seated tables evenly spaced within lab benches that project from the walls. The front of the room has a white board and large desk with a computer for teacher use and student use when permitted. There is a projector in front of the desk which allows for many opportunities to display notes, diagrams, pictures, etc. For purposes in this lesson students will travel to stations at the lab benches and also return to their desks for teacher directed instruction.(sic)

Materials

paper
pencil
Structures and Endosymbiosis quiz
Diagrams of different organisms:
-monkey
-bat
-whale
-human
Homologous/analogous/vestigal comparison worksheet

Objectives:

After completion of this lesson students will:
1) Explain the difference between homologous, analogous, and vestigial structures
2) Give an example of each of these types of structures within different organisms

Instruction:

Opening:

1) Give the students the four diagrams sheet as a single sheet of paper per table. (See Diagrams of different organisms) Where is this?
2) Students will be asked to write a response to it based on the questions: What similarities and differences do you notice between these structures? What organisms do you think these structures belong to? Can you make any connections to these structures and something you have learned previously and possibly to endosymbiosis?
3) Discuss student responses and ask students what they think the class lesson will focus on.
4) "Do you think it is possible that all these structures originated in one common ancestor? Why or why not?"
5) "By the end of today's lesson you should be able to explain why it is possible that many species originated from a common ancestor and why it is also possible that similar functioning organisms have different ancestors. You should also be able to explain the simialrities and differences in structures and functions of different organisms."

What instructions will you give the students? "Write a response to these diagrams" sounds a little vague. How about "What similarities do you see between the four diagrams? What differences do you see? What do you think each diagram represents? (No labels).
After students guess what the lesson is about, what are you going to say? How are you going to establish a need in your students' minds for the lesson that you are about to teach?

Engagement:

Mini-lecture:
Explain homologous, analogous, vestigial structures through overhead projection with definitions and examples by:
1) Having students take out paper from notes section (this is a practice that has already been established by CT)
2) Placing transparency on overhead that bullet points and gives definitions and examples of structure types (be sure to keep each section covered with a piece of paper until it is discussed to prevent certain students from jumping ahead).
3) Asking students, "Why and when might it be important to know that anatomy of different species is similar?" (if you have a pet, want to be a vet, want to understand why some animals walk on fours and some on twos and some on fins)
4) Explain, "now that we have some more background on the structure and function of body parts in different organisms, maybe we can attempt to explain why different organisms have the structures and how they use them in their habitat."

Group activity:
1) Split students into five groups for traveling together to each station set up at the lab benches.
2) Each station has two pictures of structures that may or may not look similar.
3) For each station students will have to write a paragraph explaining the function of each structure and the purpose it serves for the environment in which the organism lives (its habitat).
4) The purpose of two pictures at each station is to have students compare and contrast the structures and explain if and why these organisms would have an advantage over the other in a particular environment.
5) As students are doing this, handout the homologous, analogous, vestigial comparison sheet as a possible help for students as they are writing and discussing what to say in their paragraphs.of structures

Comparison sheet:
1) When there is about 15 minutes left in class have students turn in paragraphs and return to seats with comparison sheet that was handed out during the stations activity.
2) Explain that on this sheet are several different structures and questions regarding where and how this structure would be used and how you might classify it in terms of being a homologous, vestigial or analogous type.
3) Allow students to use text books and notes if needed to help them find the answers (p. 302-307).
4) Guiding questions: DO you know what this organism is? Where you would find it? Based on what you have seen in bone structure, what would you say this body part is similar to in other species? Is it easier to see how some very different species may have evolved from a common ancestor and how some similar species are not as related as you once thought?

How many activities do you see? I see at least three. Each should be explained, What are students supposed to do? Why? What will you be doing? Why?

Closure:

1) When there is about 5 minute left, ask students for their attention, and ask students if they think any differently about structures in different species ( hopefully, yes and they can explain why similar structures have different functions in different organisms).
2) Ask them if they can see how this lesson relates to evolution, why do some species have advantages in different environments? Make this a quick short answer to be written down and handed in as they leave class. Good question. Do you expect them to write down their answers?
3) Assign unfinished comparion sheet as homework to be checked next class.
4) Make sure students have written down in planners to study for quiz next class: structures and endosymbiosis...

Assessment:

Paragraphs will be graded and returned with comments based on depth of students' thought process.
Comparison sheets will be checked next class.
Exit questions will be read and discussed next class after quiz.
Remind students to study for Structures and Endosymbiosis quiz next lesson

Evolutionary structures